Determination of the self-association and inter-association equilibrium constants of a carboxylic acid and its mixtures with pyridine derivates

Infrared spectroscopy has been employed to determine absorptivity coefficients and the self-association equilibrium constant of 3,4,5-tris(dodecyloxy)benzoic acid in cyclohexane. The obtained value is consistent with data reported in bibliography for other similar compounds. The equilibrium constant describing ethylpyridine/carbonyl hydrogen bonds has been determined for mixtures of the above-mentioned acid and two ethylpyridine isomers. The effect of steric hindrance is discussed.